Fossils from the Miura Peninsula and its Immediate North. 33 



broad as the upper. The tubercles are mostly somewhat elongated 

 longitudinally, equal in number in the two bands, but larger in 

 the lower. Their number is about seventeen in the last whorl. 

 Between the tubercular bands and connecting their tubercles, 

 there are rounded vertical riblets, somewhat curved and turning 

 their concave sides towards the front, quite fused with the upper 

 tubercles, but separated from the lower ones by a fine sharp 

 groove. The interspaces between the riblets are flat and wider 

 than the latter. The riblets as well as the interspaces are coarsely, 

 but closely, transversely striated, the stria? being subequal or 

 unequal and commonly about six in number. The bands are also 

 very finely striated in transverse direction. On the body-whorl, 

 the periphery is formed by a row of tubercles somewhat smaller 

 than those of the infra-sutural band, but equal in number to the 

 latter. Below the periphery which may be called roundly 

 angular, the surface is spirally threaded and crossed by weak 

 longitudinal riblets which are the basal continuations of those 

 found on the flanks of the shell. 



Four specimens, none of which is perfect, being broken in 

 the apertural as well as in the apical portion. The canal, however, 

 is preserved; it is short and recurved. The number of whorls 

 seems to have been about fifteen. One specimen measures 6,5 

 millim. in diameter; the height, if complete, would be about 30 

 millim. 



Fossil occurrence. — Naganuma Zone (Naganuma). 



12. Terebra tokunagai, Yokoyama. 

 Pl. I. Fig. 13. 



Shell subulate; whorls many, somewhat concave, with two 

 suturai bands of tubercles, the one upper or infrasutural and the 

 other lower or suprasutural . The tubercles of the upper band are 

 elongated longitudinally and also somewhat obliquely with the 

 upper end directed forward, and are much larger than those of the 

 lower band which are more roundish in shape, except on the last 

 whorl in which they form the periphery; they are just as large as 

 the others, and also somewhat obliquely elongated, though in an 



